Surface defects and roughness are two essential causes for the fatigue failure of certain parts coming into contact with one another including rolling-contact elements such as roller bearings. In order to assure the longevity of such parts, technology has been developed to minimize both surface defects and roughness of machined bearing parts, albeit such technology is costly in general. No matter how perfect a finished surface might be, once placed into service it is likely to be impaired by solid debris present in a lubricating fluid typically utilized to reduce wear. To avoid this, strict requirements of lubrication filtration must be followed, which requirements are not always practical, especially with regard to system diagnostics. Further, a paramount concern is usually not the insufficient filtration but the initial particle contamination before the steady state of lubricant cleanliness can be established. As has been found in many cases, a single abusive particle is capable of doing damage to the contacting parts and materials.
Currently there exist several performance-enhancing techniques, including coatings, designed to reduce friction, wear, corrosion, erosion, and thermal degradation of metal surfaces. A fundamental obstacle is a coating binding problem, whether due to the cohesive integrity of a coating itself or adherence of the applied coating on the metallic substrate. One difficulty stems from upholding both intra-phase cohesion and inter-phase adhesion simultaneously because these two forces oppose one another with the stronger causing the weaker to fail. Symptoms of coating breakdown can usually be attributed to the differential material warp within the coating/substrate interface region due to thermal expansion, mechanical deformation, and even chemical aging. The very existence of a ubiquitously bonded rigid film with its own distinctive properties can be the backdrop for most coating failures. Newcomers such as graded coatings are being developed to smooth the surface-to-substrate transition but with much higher costs.
Ordinary engineering surfaces are built with all-bonded (static) solid media; therein the presence of contact tensile stresses is inevitable. Tensile stress, which stretches and breaks molecular bonds, is the culprit of material wear and fatigue spallation. Another setback of the all-bonded solid medium is that fatigue cracks can expand unchecked within it.
It is therefore an object of the present invention to provide a process for covering a substrate with a dynamic layer of material which will increase the fatigue and wear life of the substrate.
It is further an object of the present invention to provide a process for saturating a substrate with a surface matrix (layer) of particle clusters and irregular cavities exhibiting a chaotic hybrid topography with zero tensile stress.
It is another object of the present invention to create a surface matrix with dynamic cavities and particle clusters to accommodate liquid lubricant as well as debris particulates so that the matrix is immune to particulate indentation.
It is another object of the present invention to provide a dynamic surface matrix (layer) that can be defined as a complex, self-organizing, and adaptive system.